Localization on a physical map of the NKC-linked Cmv1 locus between Ly49b and the Prp gene cluster on mouse chromosome 6

The Cmv1 locus controls NK cell-mediated resistance to infection with murin e CMV, Our recent genetic analysis of backcross mice demonstrated that the NK gene complex (NKC)-linked Cmv1 locus should reside between the Ly49 and Prp gene clusters on distal mouse chromosome 6. We have aligned yeast artif icial chromosome (YAC) inserts in a contig spanning the interval between th e Ly49 and Prp gene clusters. This YAC contig includes 13 overlapping YAC i nserts that span more than 2 megabases (Mb) in C57BL/6 (B6) mice. Since we have identified genomic clones that span the Ly49-Prp gene region, we hypot hesize that at least one should contain the Cmv1 locus. To narrow the Cmv1 critical region, we developed novel NKC genetic markers and used these to g enotype informative backcross and intra-NKC recombinant congenic mouse DNA samples. These data suggest that Cmv1 resides on a single YAC insert within an interval that corresponds to a physical distance of similar to 390 kb, This high resolution, integrated physical and genetic NKC map will facilita te identification of Cmv1 and other NKC-linked loci that regulate NK cell-m ediated immunity.